Impulse registering device of the type used in telephone systems



Sept. 23, 1941.

IMPULSE REGISTERING DEVICEOF THE'TYPE USED IN TELEPHONE SYSTEMS Filed' July 19, 1939 Sheets-Sheet 1 c. c. PUCKETIITE 'ETAh- S 6, 9

Sept. 23, 1941.

C. C. PUCKETTE ET AL IMPULSE REGISTERING DEVICE OF THE TYPE USED IN TELEPHONE SYSTEM- Filed July 19, 1939 5 Sheets-Sheet 2 P 1941- 3. c. PUCKETTE ET AL 2,256,869

IMPULSE REGLSTERING DEVICE OF THE TYPE USED IN TELEPHONE SYSTEMS Filed July 19, 1959 s Sheets-Sheet 5 INVENTORS CHARLES CLARKE Pl/C/fETTE Y 650%. 05mm TTORNEY Patented Sept. 23, 1941 IMPULSE REGISTERING DEVICE OF THE TYPE USED IN TELEPHONE SYSTEMS Charles Clarke Puckette and George Dewar, Coventry, England, assignors to The General Electric Company Limited, London, England Application July 19, 1939, Serial No. 285,392

In Great Britain July 20, 1938 r 13 Claims.

The present invention relates to impulse regenerators, by which is meant devices of the type used in telephone systems for registering impulses during the setting up of a connection and re-emitting impulses corresponding in number to those registered. The chief object of the illvention is to provide a device of this character which is reliable in operation and of relatively simple construction.

Regenerators as such are known, and it is possible to provide such a device which is almost entirely electrically controlled and operated, though the present invention aims at the employment of mechanical means as far as possible.

In such a regenerating device the desired functions are firstly to receive on a succession of registers the impulse trains emitted by a caller, a sequence switch or cam being provided so as to receive each impulse train on a separateregister. An impulse producing machine is now necessary, capable of generating standard impulses, i. e. those having a frequency of ten per second and a break-make ratio of 2-1. Secondly, when one or more impulse trains are stored they must be counted out again, the outgoing impulses corresponding in number and sequence to those received. Thirdly, when no further impulse trains remain stored, the action of the device must cease. Fourthly, a standard interdigital pause must be provided, this pause being given by the device as the minimum time between successive impulse trains.

The invention fulfils the foregoing desiderata, by providing five small toothed wheels each of which acts as a register, though a greater or lesser number can be used if desired. Each of the wheels is acted upon by a pawl, all the pawls being mounted on a main armature operated by amagnet. A sequence cam enables only one pawl to be operated at any one time, this sequence cam being operated step-by-step at the end of each impulse train. Thus successive impulse trains register in sequence on the small toothed Wheels.

After one impulse train has been stored, release of the relay operated during the reception of each impulse train produces a disagreement between. the position of two cams.- This closes contacts which bring a step-by-step switch device into operation, the said switch operating a second sequence cam to select one of a further series of pawls, only one of which is operable at a time.

Standard impulses are then emitted to the magnet operating the selected pawl, which is impulsed and the register wheel restored stepby-step to a normal position. This counts out the number of impulses originally stored, further incoming trains of impulses being meanwhile registered on other and similar register wheels.

When a register wheel has been restored.- tov normal, impulse emission ceases and the step-bystep switch is further impulsed for a predetermined number of steps, this formingthe interdigital pause. At the end of this time, if further impulses have been stored on other register wheels, further impulsing of a similar character takes place until all of the oiT-normal register wheels are restored to their original positions. Agreement is then once more reached between the positions of the two previously mentioned cams; the associated contact springs are opened and operation of the device ceases.

In order that the nature of the invention may be properly understood, reference should be made to the accompanying drawings in which Figure 1 is a side viewof the digit storing mechanism, Figures 2 and 3 are front and side views of the device usedto start and terminate impulse sending, Figure '4 is a perspective View of the register wheels and pawls, Figure 5 is an end viewof the device as a whole; Figure 6 is a schematic plan view showing only the arrangement of cams and gearing, and Figure 7 is the circuit diagram.

It is intended to describe the general principles of the device by outlining the method of operation with reference to Figure '7; a detailed description of the mechanism will then be given. Referring to the said figure, it will be seen that an impulse receiving relay A is assumed to be connected by wires to exchange switches which have access to the impulse generating device in known manner by means of multiple wiring on the switch banks. Suitable guard arrangements of known type are provided to prevent the regenerating device from being seized by two ormore switches simultaneously. This relay A, when operated to receive impulses, changes over its contact Al and operates relay B. Contact Bl prepares to operate relay 0 later and contact B2 engages a selector in a rank of switches to which impulses are to be transmitted by applying earth potential via contact 3 and lead 2|. No further operation takes place until the commencement of the first impulse received on relay A, at which time contact A-l releases and operates relay C and also the-magnet 4. During the whole of the time of engagement of the impulse regenerator relay B remains operated, and relay 0 is operated during every impulse train, though this relay releases between trains.

The magnet 4 carries a pawl 6 which engages with the teeth of a storage wheel I and when the magnet is energised the pawl pushes the wheel one tooth in a forward direction. At the end of the impulse the magnet releases and the pawl prepares to act on the next tooth at the commencement of the second impulse. meantime, contact CI has operated the magnet 5, which on release at the end of the impulse train moves the cams 9 and I9 one fifth of a revolution in the direction of rotation of the main shaft. The result of this operation is that the contacts II close, owing to an overlapping action of the cams to be described later, andrimpulses generated by an impulse machine connected tolead 22 pass through contacts II, the wiper 23in the position shown, to the magnet I2, this magnet and its associated pawl I3 being provided for the purpose of counting out the impulses stored on the register wheel I;

This counting out process takes place at a standard rate determined by the impulse machine, the wheel 1 being turned in a backward direction to the extent of one tooth for each impulse counted out. Each time the pawl I3 is pushed forward by the magnet I2 a cam I is tilted about a pivot 51 so as to open and close the contacts 3, each such opening and closure providing an impulse of suitable length and ratio to the selector connected to lead 2I. When a number of impulses equal to those put into the register wheel have been counted out, the wheel reaches a stop with the result that the next impuls given to the magnet I2 fails to turn the wheel. By means of a mechanical device to be explained later, contact'I'I is now closed, with the result that the standard impulses from the impulse machine pass over contact II, wiper 23 in the position shown, multiple contacts in the switch bank 24, to the switch magnet 31, with the result that the switch wiper 23 steps through a space of ten bank contacts under the influence of the impulse machine, this wiper movement being also geared to the arm I8. At the end of this period of stepping, the wiper 23 once more reaches an isolated contact, and impulses are again imparted to the magnet I2 instead of'to the magnet 31 provided that any further digits have been stored in the meantime. If, however, only one such digit has been transmitted to the storage wheels the arm I8 moves the cam 9, by acting on the pin I9, so that the pawl slots in the two cams coincide. This once more opens the contact II with the result that the action of the device ceases. Release of relay A by the switches preceding the regenerating device causes release of relay B, and the device is available for use by some other switch if required.

Although one bank of 25 contacts only is shown, two such banks each subtending an arc of 180 at the wiper spindle are employed. Flve' positions of rest for the wiper 23 are provided,

and movement of the wiper from one such position to the next is adapted by means of gearing to move arm I8 through one-fifth of a revolution. The time elapsing between movement of the wiper 23 from one position of rest to the next is adapted to be of sufilcient length to ensure adequate switching time in the succeeding switch stages. This interdigital pause is of course always constant, the other bank (not shown) being connected so that similar pauses, are given'to those shown in Figure 7.

In the.

Referring now to the remaining figures it will be seen from Figur 5 that the impulse regenerator consists of a uniselector 25 of known type and a storing device mounted on the side of the uniselector. This storing device comprises the base plate 28, magnets 4, 5 and I2 mounted thereon in the positions shown in Figure 1, digit storing wheels I (Figs. 1, 4 and 6) and pawls 6 and I3 acting on the wheels. The wheels I are free to rotate independently of one another and of the spindle 21 upon which they are mounted.

Both the impulse storing magnet 4 and the impulse repeating magnet I2 carry five pawls, four only of these pawls being shown in Figure 4. The pawls 6, operated by magnet normally rest against a barrel cam 29, this cam having a series of slots around its periphery. The slots are displaced one-fifth of 360 apart in a circumferential direction, and are spaced longitudinally so as to co-operate each one with a separate pawl. The barrel cam 29 is rotated from the back of th base plate by means of the magnet 5 and its pawl 3|], the latter engaging with a ratchet wheel 3 I driving a gear train 32, the ratio of the gearing being such that every energisation of the magnet 5 rotates the cam 29 through one-fifth of a revolution. Thus it will be seen that after an impulse train the cam 29, by revolving, brings one of its slots opposite a fresh pawl.

During the reception of an impulse train the framework 34 carried by the armature of the magnet 4 moves the whole of the pawl assembly forward and backward. Only one pawl, however, i. eathe one which can fall into the corresponding slot in cam 29, can engage with teeth of a storage wheel I, this wheel alone, therefore, being rotated a number of steps equal to the number of impulses in the train. Revolution of the cam 29 at the end of the impulse train causes transfer of storage to another pawl and storage wheel. I

The armature of the counting-out magnet I2 has a framework 59 carrying a similar pawl assembly in which th pawls are numbered I3, these pawls being brought into action successively by the barrel cam 35. This cam and the wipers of switch 25 are mounted on a common spindle 49, and rotated as previously described by the V magnet 31 of the switch. All the storage wheels I are provided with centering and retaining springs 40, these acting to retain the wheels in a normal or stored position, though of course the said springs do not prevent the wheels from being moved by their associated pawls.

Each of the storage wheels I has a normal position from which it is adapted to be moved step by step by its associated pawl 6 during the reception of an impulse train and toward which normal position it is thereafter returned by its associated pawl I3 when the impulse train is repeated by the regenerator. In each wheel a slot 42 is provided'through which passes a fixed pin 43. This pin and slot are so dimensioned that the wheel can be moved no more than ten steps from its normal position by the receiving magnet and pawl 5, and the slot also serves to prevent the wheel from being returned past its zero position by the impulsing-out magnet and pawl l3.

It is now proposed to describe the method whereby the device is kept in operation so long as any digits are stored in the storage wheels. This device is shown in Figures 2 and 3, and comprises two cams 9 and I9, mounted on concentric bearings on the end of spindle 21 as shown in Figures 5 and 6. The cam I0 is driven by a gear Wheel 44 which in turn is driven by;the shaft 35 and gear wheel 46 (Figure 6), this drive being initiated by the magnet 5 through the pawl 30 and wheels 3| and 32. These two cams 9 and H] are held together by a spring 64 in such a position that slots 33 on the two cams do not agree, so that contacts H would normally be held closed. The cam 9, however, carrie a pin I9, which is acted upon by an arm I 8, this arm being rotated by the wheel 48 which is driven by wheel 39. This latter wheel is itself rotated with the cam 35 by the spindle 49 of the switch 25. The position of the cams 9 and i0 and the arm I8 is such that the slots 33 coincide in a position beneath the contacts ll only when all the impulse storage wheels 1 are in a normal position i. e. when the cams 29 and 35 have been rotated by their associated drives to such positions that no stored digits remain in the storage wheels. This may occur five times during one revolution of the cams 9 and I0, though if one or more digits remain stored, the spring 64 pulls the cam 9 into such a position that its slots do not agree with.

the slots in cam It, so that contacts ll remain closed.

When a pawl i3 carried by the member 50 engages with a storage wheel to remove the digit stored by it, the member 59 is moved backwards and forwards by means of the armature SI of the magnet l2. the member 50 by means of the flexible spring 52, this spring being tensioned so as to rest against the armature. At the end of digit sending, i. e. when a number of impulses have been counted out in a particular train equal to the number of impulses counted in, the storage wheel being acted upon is stopped by engagement of the pin 43 with the end of the slot 42. Th next energization of the magnet [2, therefore, causes the armature 5| to move to the full extent of its travel, though the member 50 is stopped by engagement of pawl IS with the storage wheel a short distance after theforward travel of the member 58 commences. This causes bending of the spring 52, with consequent closure of the contacts I1, this closure being employed as previously described to step the magnet of the switch preparing the inter-digital pause.

For convenience, five storage wheels have been provided, though less or more than thisnumber may be used if required. Even in a multi-exchange area, it is not thought likely that more than three digits will be stored and awaiting sending at any one time, so that the device has a safety margin of two digits. If the incoming impulse trains are received quicker than those which are being sent, storage takes place faster than sending, a standard inter-digital pause being always provided. If; however, the incoming trains are received slower than the maximum speed at which the digits can be sent, the impulses are sent out at correct speed and impulse ratio, though the inter-digital pause is longer than that previously produced.

The impulses sent out by the device are. obtained not from an impulse producing machine directly, but via the cam [5 which is rocked by the magnet l2 during the restoration of a storage wheel to normal. This cam I5 is pivoted on a pin 57, which is fixed to the frame 28 of the device, and carries a slot at its upper end engaging with another pin fixed to the member 50 and moving with it. The cam [5 therefore rocks each time the member 50 moves a pawl 13 to The armature 5! is connected to 0 rotate astorage'wheel step-by-step toward its zero position. This rocking motion opens and closes the contacts 3 as already described, these contacts being carried by a bracket 58 fixed to the framework of the device. This bracket 58 is fixed by means of screws Bil, which pass through elongated holes in the bracket. The bracket can, therefore, be moved in a direction transverse to the length of the cam IS. The position of the contacts 3 relative to the cam is adjusted until the ratio of the impulses sent by the device is of a particular value. Thus a 1/1 ratio may be required for acting upon a particular type of succeeding selector, or a 1/2 ratio may be required. for a different type of selector. Either. of these ratios, or any other ratio, may be obtained by suitable positioning of the contacts 3 relative to the cam l5. Should this facility not be required, the contact B2 (Figure 7) may be connected to impulse springs carried by an im-.

pulse generating. machine, the contacts 3 being then adapted to act as masking means only i. e. the contacts 3 then open slightly before and close slightly after the actual impulse producing springs on the machine. Closure of contact 3 then prevents impulses from being sent, since it would then be connected, via contact B2, in parallel with the actual impulse producing contacts.

The device as a whole is adapted to be mounted on a normal type of mounting plate of the kind used in telephone systems, the said plate carrying the associated controlling relays A, B and C, and also'sp'ark quenching condensers and the like when necessary. If required, the impulse regenerating device may be, as stated above, available in common to a number of selectors, or alternatively it may be associated with a particular selector or junction, all impulses received through'the said selector or junction being regenerated by the device.

We claim: 1

l. An impulse regenerating device of the type used in telephone systems comprising a plurality of storage wheels each adapted to store the impulses of one impulse train, means for rotating each of the wheels in one direction, further means for rotating the wheels in the other direction during sending out of impulses, and means for continuing impulsing out until all impulses counted in have been sent out.

2. An impulse regenerating device according to claim 1 in which each storage wheel is toothed,

each impulse received by the device being adapted to act on a magnet so as to move a storage wheel one tooth forward, the said wheel being rotated backwards one tooth ata time by a further magnet during impulse sending.

3. An impulse repeater comprising a plurality of rotary storage members each adapted to store the impulses of one impulse train, means operated by the received impulses for rotating each of the members in one direction, further means for rotating the members in the other direction of rotary storage members each having a normal position, means operated by received trains of impulses for rotating the members successively step-by-step in one direction from normal to store each impulse train as it is received upon a difierent member, means for rotating the members successively step-by-step in the other direction to restore them to normal and, during said rotation of each member to normal, transmitting a train of impulses corresponding to the train stored upon that member, and means operated during transmission of said impulse trains to provide a pause of predetermined minimum length between successive trains.

5. An impulse repeater comprising a plurality of rotary storage members each having a normal position, means operated by received trains of impulses for rotating the members successively step-by-step in one direction from normal to store each impulse train as it is received upon a different member, means for rotating the members successively step-by-step in the other direction to restore them to normal and, during said rotation of each member to normal, transmitting a train of impulses corresponding to the train stored upon that member, said last means including a step-by-step switch operated after each member reaches normal to select the next memher to be restored to normal.

6. In a device of the kind described, two impulse receiving circuits, a movable member having a normal position, means operated by impulses received over one of said circuits to move said member step-by-step from its normal position to another position, the distance of said other position from said normal position varying in accordance with the number of impulses received over said one circuit, and other means then operated by impulses received over the other of said circuits to return said member step-by-step to its normal position over the same path travelled in moving it to said other position.

7. In a device of the kind described, two impulse receiving circuits, a movable member having a normal position, means operated by impulses received over one of said circuits to move said member step-by-step from its normal position to another position, the distance of said other position from said normal position varying in accordance with the number of impulses received over said one circuit, other means then operated by impulses received over the other of said circuits to return said member step-by-step to its normal position over the same path travelled in moving it to said other position, and means controlled by said last means to generate a number of impulses corresponding to the number of steps required to return said member to said normal position.

8. In a device of the kind described, a movable member occupying a normal position, two motors for driving said member, means for transmitting a train of impulses to one of said motors to cause same to move said member stepby-step from its normal position to another position, the distance of said other position from said normal position varying in dependence upon the number of impulses in said train, and means effective responsive to the termination of said train of impulses to transmit a train of impulses to the other of said motors to cause same to return said member step by step to its normal position.

9. In a device of the kind described, a mova-' ble member occupying a normal position, two

motors for driving said member, means for transmitting atrain of impulses to one of said motors to cause same to move said member step-by-step from its normal position to another position, the

distance of said other position from said normal position varying in dependence upon the number of impulses in said train, means then effective to transmit impulses to the other of said.

motors to cause same to return said member step-by-step to its normal position over the same path travelled by said member in moving to said other position, and means operated when said member reaches its normal position to automatically terminate the transmission of impulses to said other motor.

10. In a device of the kind described, a plurality of movable members each occupying a normal position, means operated by successive trains of impulses to move said members successively in a particular direction from their respective normal positions, each member being moved a distance corresponding to the number of impulses in a different one of said trains, and means operated by impulses to restore the moved members to their respective normal positions in thesame order that they were moved therefrom by moving them successively in the opposite direction.

11. In a device of the kind described, a plurality of movable members each occupying a normal position, means operated by successive trains of impulses to move said members successively in a particular direction from their respective normal positions, each. member being moved a distance corresponding to the number of impulses in a different one of said trains, means adapted to be operated by impulses to restore the moved members to their respective normal positions in the same order that they were 'moved therefrom by moving them successively in the opposite direction, and means for initiating the operation of said last means after certain but not all of said members have been moved from their normal positions, thereby to restore part of the moved members to normal during the same period of time that said first means is moving another part of said members from normal.

12. In a device of the kind described, a plurality of movable members, two actuators for each member, the first for moving the member in one direction and the second for moving the member in the opposite direction, an electromagnet common to all of said first actuators and operated by impulses, means operated to render said firstactuators efiective in succession during the receipt of said impulses by said electromagnet thereby to cause the electromagnet to move the members 1 successively in said one direction, another electromagnet common to all of said second actuators and also operated by impulses, and means operated to render said second actuators effective in succession during the receipt of said impulses by said other electromagnet to cause said other electromagnet to move the members suc-' 

